The helpviewer application displays online help, with
several navigational aids including contents, text search, history,
and bookmarks. For information on using helpviewer, see the
section "Using the Helpviewer" in the Getting Help chapter in the Photon User's Guide.

The helpviewer supports online help documents
written in HTML (HyperText Markup Language). However, the
helpviewer can access only local files and
therefore can't be used as an Internet Web browser.
It also supports GIF and BMP image formats.

You can specify which HTML file to open using either Universal Resource
Locators (URLs) or topic paths.

The URL specifies the filesystem path where the help text
is located on the local network. Here's an example of a URL:

/usr/help/product/photon/user_guide/pdm.html

URLs are case-sensitive. These URLs are restricted in scope to the local help
files; they can't be used to access the Web.

A topic path comprises a number of concatenated topic titles, as defined
in the current table of contents. Here's an example of a topic path:

/Photon microGUI/User's Guide/Utilities/pdm

For convenience, the topic path is case-insensitive and may contain
the wildcard characters * or ?, where *
matches a string and ? matches
a character. The first matching topic is selected for display.

The helpviewer loads the table of contents either from
a single topic file (with a .toc extension) or from a
directory. By default the topic files are loaded from the
/usr/help/product directory. The format of topic files is
described in "Creating topic files" below.

The helpviewer uses a table of contents to organize the online
help. The table of contents is kept separate from the HTML files
themselves and is not part of the HTML definition.

Topic files must be created by hand based on your online help files.
You can create either a single topic file or a hierarchy of topic
files in different directories.

Topic files must have a .toc extension. They are text
files with one topic per line. Each topic line has the following format:

level|title|HTML or TOC file

where:

level

The heading level. A value of 1 represents a top level heading, which users can access directly from the Contents tree.

title

Text of the topic title (do not include any HTML - use plain text only).

HTML or TOC file

Either an HTML file/URL or a TOC file.

Usually there will be an entry in the topic file corresponding to each
HTML heading level in your help files. The topic title doesn't have to
be identical to the title in your help file.

Each topic can refer to an HTML file or a topic file. If the topic
refers to an HTML file, that file will be displayed when the topic
is selected. If the topic refers to a topic file, helpviewer
will read the subtopics from that file and display them, but no HTML
will be displayed.

If the HTML file is in a subdirectory of the enclosing topic,
helpviewer will scan the directory for topic files (this happens up to
topic level 4 only). You don't have to specify the topic file
explicitly in this case.

You don't have to specify the full directory path for each topic
if it's the same as the enclosing topic. For example, the topic file
shown below contains a single book with two chapters:

If the .toc files contain non-ASCII characters, they
must be in multibyte format to be displayed correctly in the Contents pane.
For information on compose sequences used by Photon, see the section
"Composing international characters"
in the Unicode Multilingual Support chapter.

The Photon ped editor allows the entry of UTF-8 characters.
For more information, see the ped man page.

You can either include your table of contents in the default table of
contents (along with our online documentation) or keep it separate and
specify where helpviewer can find the table of contents.

To include your help in the default table of contents, you must create
a top-level topic file and include it in the root help directory
(/usr/help/product). The helpviewer reads
all topic files from the root directory and sorts the topics alphabetically.

To load your own table of contents, start the helpviewer
like this:

helpviewer -T /home/user/topics.toc /home/user/home.html

The helpviewer application will then display your table of
contents and home page only. You won't be able to access the default
table of contents.